We look at art, but it rarely looks back at us. The viewer does all the staring; it’s a one-way street.

But Michael Theodore’s giant, lit-up installation “endo/exo” has eyes of its own, dozens of infrared sensors that work just as hard as anyone else who enters the front room at the David B. Smith Gallery downtown. You get the feeling it is watching you.

Step toward the 12-foot-high piece, or walk along its 28-foot face, and it reacts with determination, wands spin back and forth, lights change color, there are rumbles and clacks. It is an art machine, powered by the viewer, but it seems to have a mind of its own.

It’s a simple contraption, really, and low-tech in 2013: Theodore has placed against a wall a tangle of twisted white ropes, a web of fibrous entrails, looping floor-to-ceiling. They could be veins, muscles, guts of some sort.

In front of them is a hard, wooden grid with 45 wooden dowels attached. In front of that he has strung, flexible electrical conduit. These are the kind of materials found in anybody’s basement.

But when the sensors go, the dowels spin and rub against the ribs of the conduit, washboard style. It becomes an old-time percussion instrument. It plays itself, or you can play it, too, by waving your hands or stomping your feet.

In that regard, the piece straddles the line between something biological and something mechanical.

There is plenty of art these days, most of it digital, that reacts to the people around it, but it generally feels distant, just another electronic gadget with clever programming.

This piece feels more like an A-plus science project from a brainy 10th-grader. It’s less iPhone, more go-cart, and fully involving. Where is it separate from you, and where is it dependent? Where does the art begin and end? What part of it is endo, and what is exo?

Theodore isn’t exactly a low-tech type, so he’s making choices here. He’s a music and technology professor at the University of Colorado at Boulder and director of the school’s ATLAS Center for Media, Arts and Performance, one of the most digitally savvy places on the planet.

He makes his advanced moves farther back at Smith, displaying drawings that he creates by programming complicated line patterns into computers that do the work for him. In some cases, the machine actually manipulates a ballpoint pen that glides strategically along paper.

The best pieces are on scratchboard, flat sheets of white clay covered with black ink. The computer engages a stylus that etches away the ink. leaving a white pattern that looks like lace. It’s unlikely that you have seen anything like them before.

It all fits together snugly under the banner “organism/mechanism,” the show’s overall title. Theodore is exploring the intersection of technology and humanity. He’s letting the machines in for art’s sake, letting them work his hand and sometimes lead it.

Are the machines taking over? Definitely not, but they are moving things forward. The technology makes it all new, the human touch keeps it interesting.